[A study on maternal humoral immune responses to villous trophoblast using Epstein-Barr virus].

To determine whether or not maternal antibodies are generated during pregnancy, B lymphocytes from puerperal women were transformed using Epstein-Barr virus (EBV). Four weeks after infection with EBV human immunoglobulin (Ig) levels were measured in the culture supernatants by ELISA. In most wells infected B lymphocytes produced a great amount of Ig. The reaction of the culture supernatants from Ig-produced wells with placental tissues of their own was examined by immunohistochemically (by an indirect immunoperoxidase technique). The second layer antibody, goat anti-human Ig peroxidase conjugate was diluted to such a concentration that it did not react to placenta sections without the first layer, that is, culture supernatants. Some of supernatants were found to have IgM which reacted to syncytiotrophoblast. Such positive staining was observed in three of ten multiparous women and in one of two primigravidas. In conclusion, it seems likely that normal pregnant women recognize trophoblasts of their own and make antibodies to them.